App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 974 · 40 questions

Developer's tip (Box, list, place): A variable holds one value; a list holds many in order. Positions start at 0. push adds to the end; pop takes off the last item; length is how many items. On the phone: works offline, private. In the cloud: shared, any device, needs the internet.

1. 1.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
2. 2.💾 What does this code show? (Positions start at 0.)
   let songs = ["Stars", "Sunrise", "Rain"];
   show(songs[0]); (a) Rain (b) Stars (c) Sunrise
3. 3.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
4. 4.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.💾 What is a variable? (a) a picture (b) a named box for a value (c) a type of screen (d) a phone setting
6. 6.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) notes to read offline (d) a class leaderboard
8. 8.💾 What number does this code show?
   let points = 5;
   points = points - 3;
   points = points + 4;
   show(points);
9. 9.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Aman", "Kabir"];
   show(friends[2]); (a) Zoya (b) Aman (c) Kabir
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Art", "Science", "Music"];
    show(notes[0]); (a) Art (b) Maths (c) Science (d) Sports
11. 11.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) chat messages to friends (d) notes to read offline
12. 12.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 1 (d) 2
13. 13.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Music", "Sports"];
    show(notes[0]); (a) Art (b) Sports (c) Music (d) Science
14. 14.💾 What number does this code show?
    let songs = ["Stars", "Rain"];
    songs.push("Kites");
    show(songs.length);
15. 15.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
17. 17.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
18. 18.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the app is closed (c) the screen turns off (d) the phone is lost
19. 19.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
20. 20.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Riya", "Aman", "Zoya"];
    show(friends[0]); (a) Aman (b) Riya (c) Zoya (d) Kabir
22. 22.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
23. 23.💾 What number does this code show?
    let stars = 5;
    stars = stars - 3;
    stars = stars + 1;
    show(stars);
24. 24.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Rain", "Kites", "Ocean", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Sunrise (d) Kites
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Maths
26. 26.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Arjun (c) Kabir
27. 27.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) your last game level (d) photos on two devices
28. 28.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Meera"];
    show(friends[1]); (a) Aman (b) Riya (c) Meera
30. 30.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
31. 31.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Sports", "Hindi"];
    show(notes[2]); (a) Hindi (b) Music (c) Sports (d) Art
32. 32.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Rain", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Rain
33. 33.💾 What number does this code show?
    let notes = ["Hindi", "Music"];
    notes.push("Sports");
    notes.push("Maths");
    show(notes.length);
34. 34.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Ocean", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Ocean (d) Sunrise
36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Rain
37. 37.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
38. 38.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Music", "Art", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Maths (c) Art (d) Hindi
39. 39.💾 What number does this code show?
    let friends = ["Zoya", "Meera", "Kabir", "Riya"];
    friends.push("Arjun");
    friends.push("Aman");
    show(friends.length);
40. 40.💾 What number does this code show?
    let notes = ["Hindi", "Sports"];
    notes.push("Maths");
    notes.push("Music");
    show(notes.length);

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